Hey i'm installing a wet nitrous system and I was wondering where to get the fuel from.
Right now I have a Aeromotive FPR and the left side of it the hose goes to the fuel rail while the bottom of the FPR
the hose goes to a tiny metal line. Which one do I branch off of? Here are the two pictures:

 

The hose going to the fuel rail is pressurized. The hose on the bottom is the return line and is not pressurized.

 

If you have a FPR, there should be a port on the other side that you're not using. You can get a fitting to supply your nitrous by your FPR. If your FPR uses a -8an fitting, then you can get a -8an bulkhead to 4an fitting. Then run a braided line from there to a 4an fitting on the fuel solenoid.
Or, just cut into the stock fuel supply line with a fuel tee that came with the "import kit".

 

So which would be best, the pressurized line or non-pressurized.

 

You want the pressurized one. The one which they thoughtfully placed the rubber section which is perfect for Teeing. The other one has no pressure so it's not really good for anything except returning fuel to the tank.

What brand fuel rail is that? It looks very nice.

 

This is my setup.
http://turbosocks.com/store/index.php?main...gnsbt45s48j8e24

 

DTN, it's just a stock rail tapped and painted

 

It does not look painted. It looks polished.